public class PlayerInput : MonoBehaviour
{
    [SerializeField] float HorizontalInput;
    [SerializeField] float VerticalInput;
    private void Update()
    {
        HorizontalInput = Input.GetAxisRaw("Horizontal");
        VerticalInput = Input.GetAxisRaw("Vertical");
    }
    private void OnEnable()
    {
        HorizontalInput = 0;
        VerticalInput = 0;
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Character : MonoBehaviour
{
    /// <summary>
    /// 胶囊碰撞器
    /// </summary>
    private CharacterController cc;
    [SerializeField] float turnSpeed = 0.5f;//转向速度
    [SerializeField] float moveSpeed = 5f;//移速
    private Vector3 movementVelocity;//运动速度
    private PlayerInput playerInput;//玩家输入
    private float verticalVelocity;//垂直速度
    public float G = -9.8f;//重力

    private void Awake()
    {
        cc = GetComponent<CharacterController>();
        playerInput = GetComponent<PlayerInput>();
    }
    /// <summary>
    /// 计算玩家运动
    /// </summary>
    private void CalculatePlayerMovement()
    {
        movementVelocity.Set(playerInput.HorizontalInput, 0f, playerInput.VerticalInput);
        movementVelocity.Normalize();
        movementVelocity = Quaternion.Euler(0, -45f, 0) * movementVelocity;//操作对准相机
        //返回围绕x轴旋转x度和围绕y轴旋转y度的旋转,围绕z轴旋转z度；按照该顺序应用。
        movementVelocity *= moveSpeed * Time.deltaTime;

        //不为0时
        if (movementVelocity != Vector3.zero)
        {
            transform.rotation = Quaternion.Lerp(transform.rotation, Quaternion.LookRotation(movementVelocity), Time.deltaTime * turnSpeed);//平滑转向运动方
            //transform.rotation = Quaternion.LookRotation(movementVelocity);
        }

    }
    private void FixedUpdate()
    {
        CalculatePlayerMovement();
        //判断是否接地
        if (cc.isGrounded == false)
        {
            verticalVelocity = G;//下落速度为重力加速度
        }
        else
        {
            verticalVelocity = G * 0.5f;//落地后继续施加重力(防止下楼梯时悬空)
        }
        movementVelocity += verticalVelocity * Vector3.up * Time.deltaTime;//赋予垂直方向的速度
        cc.Move(movementVelocity);//控制器位移
    }
}

using UnityEngine;
using UnityEngine.VFX;

public class PlayerVFXManager : MonoBehaviour
{
    [SerializeField] VisualEffect footStep;//特效
    public  void Update_FootStep(bool state){
        if (state)
        {
            footStep.Play();
        }else{
            footStep.Stop();
        }
    }
}

using UnityEngine;

public class Player_Run : StateMachineBehaviour
{
    // OnStateEnter is called when a transition starts and the state machine starts to evaluate this state
    // 当转换开始并且状态机开始评估此状态时，调用OnStateEnter
    override public void OnStateEnter(Animator animator, AnimatorStateInfo stateInfo, int layerIndex)
    {
        if (animator.GetComponent<PlayerVFXManager>() != null)
        {
            animator.GetComponent<PlayerVFXManager>().Update_FootStep(true);
        }
    }
    // OnStateExit is called when a transition ends and the state machine finishes evaluating this state
    //当转换结束且状态机完成评估此状态时，调用OnStateExit
    override public void OnStateExit(Animator animator, AnimatorStateInfo stateInfo, int layerIndex)
    {
        if (animator.GetComponent<PlayerVFXManager>() != null)
        {
            animator.GetComponent<PlayerVFXManager>().Update_FootStep(false);
        }
    }

private void Awake()
{
    cc = GetComponent<CharacterController>();
    animator = GetComponent<Animator>();

    //如果不是玩家
    if (!IsPlayer)
    {
        navMeshAgent = GetComponent<UnityEngine.AI.NavMeshAgent>();
        targetPlayer = GameObject.FindWithTag("Player").transform;
        navMeshAgent.speed = moveSpeed;
    }
    else
    {
        playerInput = GetComponent<PlayerInput>();
    }
}

/// <summary>
/// 敌人行动
/// </summary>
private void CalculateEnemyMovement()
{
    //玩家和ai距离 如果大于ai停止距离
    if (Vector3.Distance(targetPlayer.position, transform.position) >= navMeshAgent.stoppingDistance)
    {
        //SetDestination:设置或更新目标，从而触发新路径的计算
        navMeshAgent.SetDestination(targetPlayer.position);
        animator.SetFloat("Speed", 0.2f);
    }
    else
    {
        navMeshAgent.SetDestination(transform.position);//呆在原地
        animator.SetFloat("Speed", 0f);
    }
}

private void FixedUpdate()
{
    if (IsPlayer)
    {
        CalculatePlayerMovement();
        //判断是否接地
        if (cc.isGrounded == false)
        {
            verticalVelocity = G;//下落速度为重力加速度
        }
        else
        {
            verticalVelocity = G * 0.5f;//落地后继续施加重力(防止下楼梯时悬空)
        }
        movementVelocity += verticalVelocity * Vector3.up * Time.deltaTime;//赋予垂直方向的速度
        cc.Move(movementVelocity);//控制器位移
    }
    else
    {
        CalculateEnemyMovement();
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.VFX;

public class EnemyVFXManager : MonoBehaviour
{
    [SerializeField] VisualEffect footStep;//特效
    public void BurstFootStep()
    {//与事件同名方法
        footStep.SendEvent("OnPlay");//启动动画
    }
}

using UnityEngine;
public class PlayerInput : MonoBehaviour
{
    public float horizontalInput;//水平输入
    public float verticalInput;//垂直输入
    public bool mouseButtonDown;//鼠标左键状态  
    private void Update()
    {
        if (!mouseButtonDown && Time.timeScale != 0)
        {//鼠标松开,且游戏未暂停时
            mouseButtonDown = Input.GetMouseButtonDown(0);//0:左键
        }
        horizontalInput = Input.GetAxisRaw("Horizontal");
        verticalInput = Input.GetAxisRaw("Vertical");
    }
    private void OnEnable()
    {
        mouseButtonDown = false;
        horizontalInput = 0;
        verticalInput = 0;
    }
}

#region State
//声明一个状态类
public enum CharacterState
{
    normal,
    Attacking
}
//创建变量
public CharacterState CurrentState;

#endregion

    /// <summary>
    /// 状态切换
    /// </summary>
    /// <param name="newState"></param>
    private void SwitchStateTo(CharacterState newState)
    {
        //Exiting State
        switch (CurrentState)
        {
            case CharacterState.normal:
                break;
            case CharacterState.Attacking:
                break;
        }
        //Entering State
        switch (newState)
        {
            case CharacterState.normal:
                break;
            case CharacterState.Attacking:
                break;
        }
        CurrentState = newState;//状态更新
    }
}

switch (CurrentState)
{
    case CharacterState.normal:
        if (IsPlayer)
        {
            CalculatePlayerMovement();
        }
        else
        {
            CalculateEnemyMovement();
        }
        break;
    case CharacterState.Attacking:
        break;
}

if (playerInput.mouseButtonDown && cc.isGrounded)
{
    SwitchStateTo(CharacterState.Attacking);
}

private void SwitchStateTo(CharacterState newState)
{
    //Clear Cache
    playerInput.mouseButtonDown = false;
    //Exiting State
    switch (CurrentState)
    {
        case CharacterState.normal:
            break;
        case CharacterState.Attacking:
            break;
    }
    //Entering State
    switch (newState)
    {
        case CharacterState.normal:
            break;
        case CharacterState.Attacking:
            break;
    }
    CurrentState = newState;//状态更新
    Debug.Log("当前状态:" + CurrentState);
}

public void AttackAnimationEnds()
{
    //切换到普通状态
    SwitchStateTo(CharacterState.normal);
}

#region Player slides
private float attackStartTime;//攻击开始时刻
public float attackSlideDuration = 0.4f;//攻击时长
public float attackSlideSpeed = 0.006f;//攻击速度

#endregion

/// <summary>
/// 敌人行动
/// </summary>
private void CalculateEnemyMovement()
{
    //玩家和ai距离 如果大于ai停止距离
    if (Vector3.Distance(playerTarget.position, transform.position) >= navMeshAgent.stoppingDistance)
    {
        //SetDestination:设置或更新目标，从而触发新路径的计算
        navMeshAgent.SetDestination(playerTarget.position);
        animator.SetFloat("Speed", 0.2f);
    }
    else
    {
        navMeshAgent.SetDestination(transform.position);//呆在原地
        animator.SetFloat("Speed", 0f);
        SwitchStateTo(CharacterState.Attacking);//切换到攻击状态
    }
}

if (!IsPlayer)
{
    //攻击前转向玩家
    Quaternion newRotation = Quaternion.LookRotation(targetPlayer.position - transform.position);
    transform.rotation = newRotation;
}